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w, C. BHTNTON, JR. MEANS FOR INCREASING THE DIVELECTRIC STRENGTH 0ECONDENSERS.y

l APPLICATION FAILED OCT. 17| 1918- 1,41 4,6 1 9 Patented May 2, 1922.

TTT-NIIIITWW will" EVLLIAM BRIITTON, JR., OF KENNETT SQUARE,PENNSYLVANIA, ASSIGNOR, BY MIESNE ASSIGNENTS, TO PHILBRIN CORPORATION,0F KENNETT SQUARE, ENN SYLVANIA.. A CORPORATION OF DELAWARE.

I1""NS FOR NCRESING THE DIELECTRC STRENGTH OF CONDENSERS.

finiamo.

.application filed otober 17, 1918.

To (1.7i fr/.Iom- 7'2 may romena:

lle it known 'that l, WinLiAii C. BiiiNToN, Jr.. a citizen of' theUnited States, residing at Kennett Square. county of Chester, andf'itate ot Pennsylvania.. have invented a new and uset'ul Improvement inMeans for Inf creasing the Dielectric Strength of Condensof which thefollowing is a full, clear, and exact description. reference being hadto the accoinpai fing dra-wings. which form a part oil thisspecification.

ln ignition systems for internal eonibustion engines, in 'wirelesstelegraphy, and in inany other situations. the provision ot' condeiiscrswhich will resist all conditions, norinal and abnormal, tending to breakthe-in down.`lias seemed to present an insoluble problem. The provisionof acondenser which will stand up under all normal conditions is initselil a task of great diliculty, but even it such a condcnsei-,beprovided, there are certain abnormal conditions which will break down anabsolutely yperfect condenser. 'llie chief of these abnormal conditionsis the breakage, accidental or deliberate, of the secondary circuit.Acciden* tal breakage ot' the secondary circuit cannot always beavoided. although careful Workniansliip niininiizes the risk. No 'welltrained engineer will deliberately open `the secondary circuit: butelectrically controlled apparatus is frequently operated bycoinparatively ill -trained or ignorant operators; the opening of thesecondary circuit alioids aconvenient means, for example, for slowingdown an internal combustion engine: or it iiiay be, and frequently is,opened eXperimentally to determine how the engine Will operate undersuch conditions.

ln the norinal operation, for example, of an ignition system, thesecondary circuitis induced by the opening of the primary circuit, theprimary circuit being repeatedly rapidly opened and closed by ineans .ofa vibrator or a contact maker and interrupter. The self-inductionproduced by the opening oi' the primary circuit raises its voltage andwhen the pri-mary circuit is closed, the condenser impresses its liighvoltage upon they 'primary circuit. lf the secondary circuit remainsbroken, the resulting mounting `voltage in the secondary coil causes thevoltage of the primary circuit to rapidly increase :tar above normal,imposing a strain upon Specification of Letters Patent.

I Patented May 2, i922.,

Serial No. 253,582.

the condenser far beyond that Which it is designed to resist. Hence,even though the condenser be absolutely perfect in its construction,with a reasonable margin of safety in the Way of capacity andvdielectric strength, it breaks down under the extraordinary strain. Thebreaking down of the condenser paralyzes the Whole System and niay oftenproduce the inost serious results.'

v T he danger exists to its ina-xiinum extent when the voltage risesrapidly. An eihcient condenser can stand an actually abnormal Voltageprovided the increase in voltage is gradual, but not if the increase issudden.

I have Solved the problem of building up 'the dielectric strength of acondenser so that invention presents the following characteistics. Aplurality of condensersc preferably two, are arranged in the condensercircuit. They n'iust be arranged in parallel and not iiiv series. Theymust be of different capacities. Their total capacity need only be thesaine as the calculated capacity of asinglo condenser adapted to meetnormal conditions. .f

The accompanying drawing is a diagram showing the application ot theinvention to the ignition system of an internal combustion engine,although it will be understood that this is only one of niany possibleapplications.

A source of current supply, a, which may be assumed to be a storagejoattery, is grounded at one side, While its other side is connected tothe primary winding b of an induction coil: rl`he Winding b connectswith a contact maker and interruptor c actuated roin an engine-drivenshaft (l. The secondary winding c' of the induction coil .is grounded.at one side, ivlliile its other side is connected to a. distributor f,the rotating blade g of Which (driven from shaft closes the secondarythrough the spark plugs or' a plurality of. engine cylinders, onecylinder h and spark plug being shown. I prefer that the contact makerand interruptor shall have the specific construction shown in the Brownand Brinton Patent No. 1,234,278, issued July 24, 1917. The distributormay be constructed in accordance with Brinton Patent, No. 1,227,109,issued May 22, 1917.

in the primary circuit, in shunt with the contactmaker and interruptor,are two conolensers m and n, arranged in parallel. llhese condensers areshown as of different size as a diagrammatic Way of illustrating theirdifferent capacities. lf the two condensers are of precisely the same.capacity, they are apparently no improvement over a single condenser. Ihave not determined, with absolute accuracy, what percentage ofvariation in capacity is a prerequisite to' success, but I have triedcondensers Whose respective capacities Vary as little as two per cent.and have found that they broke down,

under conditions` y producingv a sudden mounting of voltage, about asquickly as a single condenser, while if the variation in capacity isincreased to eight per cent the condensers vwill stand upnnderconditions which are invariabl fatal where a single condenser, oritsequ1valents-a plurality ot condensers in series or a plurality 'ofcondensers of the same capacity in parallclare used.

The observed phenomena in the case of a sudden increase in voltage Withthe use of a single condenser is, first, violent sparking and then, orperhaps simultaneouslyLthe burning of the condenser, thus destroying,g`its properties. Where my invention is einn ployed, there is no sparking,and the condensers are not deleteriously affected, but take care of thehighest voltage which can be created by the deliberate breaking of thesecondary circuit. As above stated, l have i'ound it unnecessary toincrease the 'totalcapacity ofthe ltwo condenser beyoiid that which isrequired for. a single condenser that ,is designed for normal working'conditions.

The condensers that l have successfully employed are constructed inaccordance with the Brinton Patent No. 1,237,015, issued .August 14,1917; and also embody the specific improvements set forth in my appliIcations, Serial No. 181.735. filcd July 20.' 1917, and Serial No.206.900, ilcd December My theory of the electrical action that accountsfor the abilit \v oi' a pair of parallel unlmlanccd condenscrs towithstand a tar greater and more sudden increase ot' voltage than asingle condenser ot' greater capacity is that there occurs a surging`oi' the current back and Jorth from one condenser to another. eacllicondenser momentarily taking up the shock while the dielectric strengthof' the other is buildingr up. l do not feel warranted, however. inadvancing too con iidently any scientific theory to account for theobserved result. The prccise action may be too obscure to be withcertainty discoverable. However, this exact knowledge is unnecessary tothe practice ot' the invention, it being only necessary to follow thesimple instructions herein contained to avoid the breaking,rdoivn'heretotore deemed to be an inevitable consequence of a suddenmarked increased in voltage.

Havingr now fullydcscrihed my invention, what I claim and desire toprotect by lietters Patent is:

l. rlhe combination of a primary and a secondary circuit having' aninduction coil connected thereto, a malte and break device, and alurality et' condensers ot dili'erent capacities connected in multipleto each other in the primary circuit.

2. An ignition system Jtor internal ecmbustion engines having aninduction coil, a primary circuit-connected in series ivith'a source otelectrical energy, `the Aprimary winding of the induction coil and aninterrupter, a secondary circuit connecting the secondary Windiin;1 ofthe induction coil, a

distributor and asparlr plug: in series, and

a condenser having a plurality of units oi? substantially difercntcapacities connected in parallel with eachother and shunting theinterruptor.

3. An ignition system 'for combustion. engines comprising an indue-tioncoil having a primary winding and a secondary Winding. a source ofelectric energy` an interruptw, a plurality oic condcnscrs ot diiiicrcutcapacities, a distributor, a spark plug. a secondary circuitconnecting),r the secondary winding ot the induction coil, thedistributor and spark plug in series with each other. anda priu marycircuit connecting'the condensclrs and intcrrupter in multiple with eachother and in scrics with thc primary winding' of 'the induction coil andthe. source ci energy.

ln testimony of which invention, l have hcrcunto set my hand` at KennettSquare, la., on this eleventh day oi October, 1918.

Vif'LLIAll/i (l. BlllNTON, die.

